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.NET
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Not in CISA KEV
MEDIUM severity

CVE-2025-49015 — CouchbaseNetClient

MEDIUMFix: couchbase/couchbase-net-client@04d1679

CVE-2025-49015 is a medium-severity (CVSS 4.9) CWE-297 vulnerability in CouchbaseNetClient. A fix is available for CouchbaseNetClient — see the affected versions and patch details below.

Couchbase .NET SDK (client library) does not properly enable hostname verification for TLS certificates

Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Nov 4, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2025-49015.

EPSS Exploitation Probability

via FIRST.org ↗
0.2%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs14th percentile — riskier than 14% of all scored CVEsHighest risk
0.00%0.24%0.49%0.73%0.2%0.2%May 26Sep 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected
.NETCouchbaseNetClient

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.

Description

The Couchbase .NET SDK (client library) before 3.7.1 does not properly enable hostname verification for TLS certificates. In fact, the SDK was also using IP addresses instead of hostnames due to a configuration option that was incorrectly enabled by default.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
.NETNuGetCouchbaseNetClientall versions3.7.1dotnet add package CouchbaseNetClient --version 3.7.1

Affected Products

1 product · 1 configurations
Application
.net sdkcouchbase
≤ 3.7.1
range

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for CouchbaseNetClient, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update CouchbaseNetClient to 3.7.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-49015 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

The Couchbase .NET SDK (client library) before 3.7.1 does not properly enable hostname verification for TLS certificates. In fact, the SDK was also using IP addresses instead of hostnames due to a configuration option that was incorrectly enabled by default.
O3 Security · Impact-Aware SCA

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CVE-2025-49015: CouchbaseNetClient — Fixed in 3.7.1